Substitution parameters define parameters that have a constant value for one environment, but the value can be changed for use in other environments. Make a change in one location to affect all jobs. You can override the parameter for particular job executions.
The typical use case is for file locations that are constant in one environment, but change when a job is migrated to another environment, for example, migrating a job from test to production.
As with variables and parameters, the name can include any alpha or numeric character or underscores, but cannot contain blank spaces. Follow the naming convention and begin the name for a substitution parameter with double dollar signs ($$) and an S_ prefix to differentiate from out-of-the-box substitution parameters.
Substitution Parameters vs Global Variables
| Global Variables | Substitution Parameters ($$) |
|---|---|
| Can be used in transforms, functions and scripts. | Can be used in transforms, functions and scripts. |
| Assigned default values can be overridden at execution time. | Assigned default values can be overridden at execution time. |
| Defined at the job level. | Defined at the repository level. |
| Cannot be shared across jobs. | Available to all jobs in a repository. |
| Data type specific. | All strings with no data type. |
| Value can change during execution. | Fixed value set prior to job execution. |
Select Substitution Parameter Configurations from the Tools menu to create a substitution parameter configuration.
Let me show you an example:
Caution
When exporting a job to a file or a repository, the substitution parameter configurations are not exported with them. Export substitution parameters via a separate command to a text file and use this text file to import into another repository.Datastore Configurations
Something else that depends on the environment is the datastore setup.
The type, name, or user of the database can be different.
You can define several datastore configurations, just like you do for substitution parameters.
System Configuration
Once you have defined several configurations for substitution parameters and datastores, you need to define a system configuration to apply during execution.
Each system configuration corresponds to a specific configuration for the substitution parameters and each datastore.
You must then define the system configuration you want the job execution to apply.
Let me show you how to create such configurations:
